MONTPELIER — The Vermont Human Rights Commission announced Thursday it has joined the business manager at the Windsor state prison in a lawsuit, alleging she receives less pay than her male Springfield prison counterpart because she is female.

The lawsuit, filed in Washington Superior Court, said Rutland prison business manager Lynne Silloway was making $24.65 per hour, while the only male manager among the seven business managers at Vermont’s state prisons was making $29.59 per hour as of July. The suit said the difference works out to about $10,000 a year.

“The state of Vermont should be a leader in fair employment practices, and needs to be held fully accountable under the law,” Robert Appel, the commission’s executive director, said in a statement announcing the lawsuit.

Appel said he had recommended that all the business managers be given raises to bring them in line with the male manager, the best paid among them.

Corrections Commissioner Andrew Pallito and Human Resources Commissioner Kate Duffy, whose departments were named as defendants in the lawsuit, said the extra pay going to Springfield business manager Mike Foisy was not a function of gender bias. They said the difference is the result of Foisy’s transfer into a job from another position at Springfield and from the state’s system of pay grades and step raises given for years of experience.

“This administration is very committed to equal pay for equal work,” Duffy said. “We operate under a merit system in our collective bargaining agreements ... There are plenty of times in this system where you’re not paying people (in parallel jobs) exactly the same thing, and it has nothing to do with their sex.”

Each of the state’s seven prisons has a business manager — officially known as the administrative services coordinator.

The lawsuit referred to Foisy as “Mr. Doe;” Pallito identified him in a telephone interview.

Appel described as “malarkey” the state’s claim that it was locked into the different pay rates by its contract with the state workers’ union, the Vermont State Employees’ Association. He said nothing in state law or the union contract would have prevented state officials from following his suggestion that the other business managers be given raises.